The present invention relates to a novel potato variety designated ‘Shelford’ and to the tubers, plants, plant parts, tissue culture and seeds produced by that potato variety. All publications cited in this application are herein incorporated by reference.
The potato is the world's fourth most important food crop and by far the most important vegetable. Potatoes are currently grown commercially in nearly every state of the United States. Annual potato production exceeds 18 million tons in the United States and 300 million tons worldwide. The popularity of the potato derives mainly from its versatility and nutritional value. Potatoes can be used fresh, frozen or dried, or can be processed into flour, starch or alcohol. They contain complex carbohydrates and are rich in calcium, niacin and vitamin C.
To keep the potato industry growing to meet the needs of the consuming public, substantial research and development efforts are devoted to the modernization of planting and harvesting of fields and processing of potatoes, and to the development of economically advantageous potato varieties. Through crossbreeding of potatoes, researchers hope to obtain potatoes with the desirable characteristics of good processability, high solids content, high yield, resistance to diseases and pests and adaptability to various growing areas and conditions.
The U.S. acreage planted in potatoes has declined since the 1960s and 1970s, and this decline, coupled with increasing consumption, must be offset by higher useable yields. In some areas, diseases and pests damage crops despite the use of herbicides and pesticides. The problem of the golden nematode in the United States, presently endemic to portions of New York State, is one example of the destruction to susceptible potato varieties. Potato varieties with high yields, disease resistance and adaptability to new environments can eliminate many problems for the potato grower and provide more plentiful and economical products to the consumers.
For the potato chip processing industry, potatoes having high solids content, good shipping qualities and good finished chip color can increase production volumes and efficiencies and product acceptability. Potato varieties which yield low-solids tubers result in unnecessary energy usage during the frying process. Moreover, as solids content increases, the oil content of fried products decreases, which is a favorable improvement. Potato varieties in the warm southern tier of states are most in need of solids improvement overall, while those varieties grown and stored in the colder northern tier of states are most in need of the ability to recondition after cool or cold storage to increase their value for use in the potato chip industry. Reconditioning is necessary to elevate the temperature of the potatoes after cold storage and before further processing.
The research leading to potato varieties which combine the advantageous characteristics referred to above is largely empirical. This research requires large investments of time, labor, and money. The development of a potato cultivar can often take up to eight years or more from greenhouse to commercial usage. Breeding begins with careful selection of superior parents to incorporate the most important characteristics into the progeny. Since all desired traits usually do not appear with just one cross, breeding must be cumulative.
Present breeding techniques continue with the controlled pollination of parental clones. Typically, pollen is collected in gelatin capsules for later use in pollinating the female parents. Hybrid seeds are sown in greenhouses and tubers are harvested and retained from thousands of individual seedlings. The next year one to four tubers from each resulting seedling are planted in the field, where extreme caution is exercised to avoid the spread of virus and diseases. From this first-year seedling crop, several “seed” tubers from each hybrid individual which survived the selection process are retained for the next year's planting. After the second year, samples are taken for density measurements and fry tests to determine the suitability of the tubers for commercial usage. Plants which have survived the selection process to this point are then planted at an expanded volume the third year for a more comprehensive series of fry tests and density determinations. At the fourth-year stage of development, surviving selections are subjected to field trials in several states to determine their adaptability to different growing conditions. Eventually, the varieties having superior qualities are transferred to other farms and the seed increased to commercial scale. Generally, by this time, eight or more years of planting, harvesting and testing have been invested in attempting to develop the new and improved potato cultivars.
Long-term, controlled-environment storage has been a feature of the northern, principal producing areas for many years. Potatoes harvested by October must be kept in good condition for up to eight months in temperatures that may drop to −30 degrees C. at times and with very low relative humidity in the outside air. Storages are well insulated, not only to prevent heat loss but also to prevent condensation on outside walls. The circulation of air at the required temperature and humidity is automatically controlled depending on the purpose for which the potatoes are being stored. Sprout inhibition is now largely carried out in storage as it has been found to be more satisfactory than the application of maleic hydrazide (MH30) in the field.
Proper testing of new plants should detect any major faults and establish the level of superiority or improvement over current varieties. In addition to showing superior performance, a new variety must be compatible with industry standards or create a new market. The introduction of a new variety will increase costs of the tuber propagator, the grower, processor and consumer for special advertising and marketing, altered tuber propagation and new product utilization. The testing preceding release of a new variety should take into consideration research and development costs as well as technical superiority of the final variety. Once the varieties that give the best performance have been identified, the tuber can be propagated indefinitely as long as the homogeneity of the variety parent is maintained.
For tuber propagated varieties, it must be feasible to produce, store and process potatoes easily and economically. Thus, there is a continuing need to develop potato cultivars which provide good processability out of storage, with minimal bruising, for manufacturers of potato chips and other potato products and to combine this characteristic with the properties of disease and pest resistance. The present invention addresses this need by providing the new variety as described herein.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification.